hayes



Sept. 24, 1963 s. A. HAYES MIXING APPARATUS 4 Sheets-Sheet 1 OriginalFiled June 30, 1958 IN V EN TOR. STANLEY A. HAYES M imam A TTORNEVSSept. 24, 1963 s. A. HAYES MIXING APPARATUS 4 Sheets-Sheet 2 OriginalFiled June 50, 1958 Sept. 24, 1963 s. A. HAYES 3,104,825

MIXING APPARATUS Original Filed June 50, 1958 4 Sheets-Sheet 3 YA/WAlf/AVA v w A V A Arman/5V5.

Sept. 24, 1963 s. A.'HAYES 3,104,825

MIXING APPARATUS Original Filed June 50, 1958 4 Sheets-Sheet 4 INVENTOR.5774/1/46? 4. H4765 United States Patent "ice 14 Claims. (Cl. 239-407)The present invention relates generally to mixing devices and moreparticularly to .apparatus for mixing a first liquid into the carrierstream of a second liquid.

This application is a continuation of my copending application SerialNo. 746,312, filed June 30, 195 8, now abandoned, which is acontinuation-impart application of my preceding application Serial No.497,106, filed March 28, 1955, now forfeited.

Apparatus capable of mixing a first liquid into a carrier stream of asecond liquid have many diiterent uses such as mixing fertilizer inirrigation Water, adding detergent to a water stream for washingarticles and applying liquid chemicals such as insecticides, toxicantsand fungicides to plants, trees shrubs, lawns and agricultural crops.

Various types of prior art apparatus for mixing first and second liquidshave been widely used. For example,

garden hose sprayers of the type disclosed in my earlier patent, No.2,592,896 function to educt a chemical solution into a carrier stream ofwater under pressure from a garden hose connected to a city watersystem. Such garden hose sprayers employ a jet pump eductor of a specialtype which is capable of maintaining a constant ratio of eductedchemical to water over varying water pressures. While such prior art jetpump eductors operate very satisfactorily from a garden hose, sucheductors are not suitable for use in series with sprinkling apparatuswhich places a high back pressure on the eductor since such eductorswill operate only over a very limited range of back pressures.

For example, prior art eductors have not operated satisfactorily whensuch an eductor is connected in series with a number of sprinklers whichrequire a large pressure drop across the sprinklers to provide coverageover a large area. This problem may be remedied by placing a pump in thesystem downstream from the eductor to restore pressure in the carrierstream of the second liquid (i.e. water) after the first liquid (i.e.chemical) has been educted into it. The use of such .a pump is expensiveand diflicult to maintain where the educted liquid is corrosive orotherwise harmful to the pump.

Such prior art eductors are also unsatisfactory for portable systemswhich employ a pump with a length of hose such as 50 feet connectedbetween the pump and the eductor to permit a wide area to be coveredwithout moving the pump. The operator is required tocalry a largequantity of chemical with the eductor or a separate hose is required toconnect a chemical container located adjacent the pump with the eductor.This is not practical where wettable powders and other materials that donot completely dissolve are to be sprayed since such ma terials willsettle out in the suction hose carrying the slow moving chemicalsolutions and impair the operation of the sprayer.

The above disadvantages of prior art eductor apparatus are overcome bythe present invention. This invention provides mixing apparatus whichutilizes the eductor principle to introduce a first liquid (chemical)into a carrier stream of a second liquid (water) without imposing aserious pressure drop in the carrier stream and it is operable over awide range of back pressures on the mixing apparatus. Another advantageof this invention is that it permits the first liquid to be mixed intothe second liquid on the discharge or high pressure side of a pump andPatented Sept. 24, 1963 2. thereby avoids the passage of the firstliquid which may be corrosive through the pump.

In accordance with the present invention, there is provided a mainconduit adapted to be connected to a source of a second liquid such aswater. A bypass conduit opens into the main conduit at an upstream and adownstream location. A first or chemical eductor is disposed in thebypass conduit and includes an inlet passage, an aspiration chamber,.and an outlet passage arranged in that order. Conduit means areconnected between the aspiration chamber of the first eductor and asource of the first liquid (i.e. chemical). A second or power eductor isdisposed in the main conduit and includes an inlet passage, a mixingchamber and an outlet passage arranged in that order. The mixing chamberof'the second eductor is connected to the bypass conduit at thedownstream location of the main conduit whereby the first liquid iseducted into a carrier stream of the second liquid in the first eductorand the discharge stream from the first eductor flowing in the bypassconduit is educted into the second liquid flowing through the secondeductor in the main conduit. The

inlet passage of the second eductor may comprise a section of reduceddiameter in the main conduit disposed adjacent the downstream locationWhere the bypas conduit joins the main conduit. The reduced diametersection is in educting relationship with the portion of the bypassconduit between the eductor in the downstream location.

In the preferred form of the present invention, valve means .aredisposed in the main conduit between the upstream and downstreamlocations for controlling the ratio of the second liquid flowing throughthe bypass and main conduits. Where the second liquid may be obtainedfrom a source at a substantially constant pressure, for example, aconstant pressure discharge pump, almost any type of well known jet pumpeductor may be used in the bypass conduit to educt the first liquid.However, when the source of the second liquid is such that there aresubstantial pressure fluctuations, for example, a municipal water supplyor variable pressure discharge pump, a first eductor of a specialconfiguration such as disclosed in United States Patent No. 2,592,896should be used when it is desired to maintain a constant proportion ofthe first liquid with respect to the second liquid.

The invention will be more fully understood from the following detaileddescription taken in conjunction with the accompanying drawings inwhich:

FIG. 1 is a schematic diagram showing the use of the invention in aportable mixing system, which may be used for washing operations;

FIG. 2 is an elevation of one embodiment of the invention used forwashing operations;

FIG. 3 is an enlarged fragmentary sectional elevation of the areaenclosed by line 3-3 of FIG. 2;

FIG. 4 is a plan view of the mixing chamber taken on line 44 of FIG. 2;

FIG. 5 is a sectional elevation taken on line 55 of FIG. 4;

FIG. 6 is a longitudinal sectional elevation of another embodiment ofthe mixing device for use in watering systems;

FIG. 7 is a view taken on line 7-7 of FIG. 6;

FIG. 8 is a schematic elevation of a. watering system using the mixingdevice shown in FIGS. 6 .and 7;

FIG. 9 is a schematic elevation of an alternate mixing device of theinvention;

FIG. 10 is a view taken on line 10-10 of FIG. 9;

FIG. 11 is a longitudinal sectional elevation of another embodiment ofthe invention; and

FIG. 12 is a longitudinal sectional elevation of the presently preferredembodiment of the mixing device for use in watering systems.

Referring to FIG. 1, a pump 10 having a suction line 11 disposed in areservoir 12 of a carrier fluid or second liquid 14 is connected todischarge the carrier liquid into a main conduit 16. A first or chemicaleductor 18 is connected in a bypass conduit or line 19 opening into themain conduit at an upstream location 20 and a downstream location 2-1.Aside leg 22. on the eductor 18 extends into a reservoir 23 containing afirst fluid or liquid 24 to be introduced into the carrier liquid. Themain conduit includes a section 25 of reduced diameter in the mainconduit adjacent the downstream location. The section 25 of reduceddiameter in the main conduit forms the inlet passage of a second eductordisposed in the main conduit 16. This second eductor includes an outletpassage 25A of larger cross sectional area than the inlet passage 25 anddisposed downstream from the junction 21 of the main and bypassconduits. A mixing chamber is disposed between the passages 25 and 25Aand permits the discharge stream from the reduced diameter section 25 todirectly contact the combined stream of first and second liquids flowingfrom the eductor 18 and through the bypass conduit 19 for entrainingthis material into the first liquid flowing through the main conduit 16.

The operation of the system of FIG. 1 is as follows: The pump deliversthe carrier liquid, such as water, through the main conduit 16 and thesecond eductor including the passages 25 and 25A to provide a pressuredrop between the points 2% and 21 Where the bypass conduit joins themain conduit. This pressure differential causes some of the carrierliquid to pass through the first eductor 18 and suck the first liquid upthe side leg into the stream of carrier liquid flowing in the bypassline. The combined stream of carrier and first liquid leaving theeductor 18 is discharged into the bypass conduit which is connected tothe mixing chamber of the second eductor at junction 21. The stream ofcarrier and first liquid passing through the bypass conduit is forcedinto the mixing chamber of the second eductor where it is entrained withthe carrier stream discharged from the inlet passage 25 of the secondeductor. The outlet passage 25A of the second eductor functions as a.diflusion passage for confining (or sealing) the liquid streams flowingfrom the main and bypass conduits and allows the transfer of energy fromthe high vel-ocity'discharge stream from the inlet passage 25 to thestream issuing from the bypass conduit 19. As a result of the action ofthe second eductor the stream leaving the outlet passage 25A of thesecond eductor is a completely mixed high velocity stream. The fluidpressure in the mixing chamber of the second eductor at the downstreamjunction 21 of the main and bypass conduits may be much lower than thepressure in the main conduit 16 downstream from the outlet passage 25 ofthe second eductor. This provides a relatively high pressuredifferential across the first eductor 18 to provide efiicient eductionof the first liquid into the bypass conduit while providing a relativelysmall overall pressure differential across the second eductor. Theeificiency of the apparatus of FIG. 1 in which two eductors are providedwith the first eductor delivering a mixture of the first liquid and thecarrier liquid into the mixing chamber of the second eductor is veryhigh. This high efiiciency results from the action of the second eductorwhich efiiciently converts the potential energy in the high pressurewater stream into kinetic energy in the inlet passage of the secondeductor and back to potential energy in the outlet passage of the secondeductor in the form of pressure downstream from the outlet passage ofthe second eductor. It should be noted that the pressure in the mixingchamber of the second eductor at the junction 21 of the main and bypassconduits may be greater or l ss than atmospheric pressure depending uponthe relative size of the passages at the first and second eductors andthe inlet pressure of the carrier stream at the junction 20 of the mainand bypass conduits. For this V 4; reason the inlet passage 25 of thesecond or power eductor is referred to as being in educting relationshipwith the portion of the bypass conduit connected to the main conduit atthe downstream location 21 instead of aspirat ing relationship since theword aspirate implies a pressure below atmospheric.

Referring to FIGS. 2 through 5, a main conduit 26 comprises acylindrical main conduit chamber 28 having an inlet end provided with asuitable fitting 30 to be connected to a flexible hose (not shovm) whichsupplies a carrier liquid from a suitable source, such as a pump (notshown). The discharge end of the main conduit chamber is provided with acoupling 32 by which it is connected to a plurality of sections 34 ofrigid tubing which form the outlet end of the main conduit which in turnis connected to mixing head 36 as described in dc opening in the mainconduit chamber to form the inlet.

portion of a bypass line 39. One end of a chemical eductor 49 is screwedinto the end of the elbow fitting remote from the main conduit chamberand the other end of the chemical eductor is coupled to a plurality ofsections 42 of rigid tubing which in turn is connected to the mixinghead as described below.

Referring to FIG. 3, the chemical eductor comprises a nipple 44 threadedexternally at its inlet end and internally at its discharge end. Thenipple is provided with a passageway formed in three stepped sections45, 46 and 47, each succeeding section from the nipple inlet to Oil! letbeing of slightly smallerdiameter than the preceding section. Theinterior of the nipple adjacent the out let end of section 47 tapersoutwardly to a threaded bore 48 of substantially larger diameter thanany of the preceding sections. The nipple is provided with a hexagonalexterior 5% intermediate its ends (see FIG. 2) to facilitate itsassembly and disassembly in the bypass line.

A sleeve 52 of substantially the same length of section 46 ispress-fitted into that section. The sleeve is provided with an externalannular groove 54 about its center and a bore 56 in the annular groove,the bore being aligned with a larger side bore 58 provided in the centerof the nipple. Bore 58 is threaded internally to receive one end of asuction leg 60 having its other end connected to a source of a firstliquid (not shown) to be introduced into the carrier liquid. Thedischarge end of the suction leg is provided with an enlarged bore 62which houses a check ball 64 which in turn is caged by a half-moon disk65 friction fitted into a longitudinal slot 66 in the interior of thedischarge end of the suction line and outwardly of the check ball.

' The mixing head (see FIGS. 2, 4, and 5) comprises a relatively thinupright rectangular body 68 having a horizontal first liquid inlet 70and a carrier liquid inlet 72 disposed directly below the first liquidinlet, both inlets being in the rear surface of the head. The inlet endof the carrier liquid inlet is threaded internally to receive thedischarge end of the main conduit and is tapered at its opposite end toa section 74 of reduced diameter which extends through the body adjacentthe forward surface of the head when it is stepped up in diameter toform a section 76.

The discharge end of section 74 is threaded internally to receive anexternally threaded jet 78 having a stepped bore '79 through its bodyincluding sections 80, 81 and 82, each section from inlet to outletbeing of smaller diameter than the preceding section, and each sectionbeing connected by short tapered portions. An intermediate portion '83of the jet exterior is of hexagonal shape sausa e tapered from anintermediate portion of the here to form a reduced opening 88 at thenozzle discharge end, the tapered portion of the nozzle serving as amixing chamber 39 for the fluids emerging from the main conduit and thebypass conduits.

The mixing head is provided with a vertical bore Q53 in its upper endformed in 4 stepped sections 91, 92, 93 and 94, each succeeding sectionfrom the exterior to interior being of smaller diameter than thepreceding, section 94 being short with respect to the other sections andterminating just above section 74. The lower portion of section 93 isconnected to the first liquid inlet by curved bore 96 cast into themixing head. The intermediate portion of section 92 is connected to theannular space 84 around the jet by a curved passageway 98 cast in themixing head. The shoulder formed by the sections 92 and 93 is providedwith an annular groove 1% which forms a raised shoulder 192.

The upper end of section 92 is threaded to receive a packing gland nut164 having a flange 1% at its upper end which seats on an O-ring 11*;8resting on the shoulder formed between sections 91 and 92. A verticalcentral bore 116 is formed through the length of the packing gland nutand is provided with an internally projecting ring 112 in itsintermediate portion. A valve push rod 114 is disposed through the bore116 in the packing gland nut and is provided with a section 116 ofreduced diameter at its lower end to slide snugly through the ring inthe bore of the paclcing gland nut. An O-ring 118 is disposed in theannular groove 119 in the portion of the push rod that travels in thering during the operation of the valve to insure a fluid tight seal. Thelower end of the packing gland nut is provided with sections 124 and 121of reduced diameter, section 121 being at the extremity of the nut andof the smaller diameter. Section 121) forms an annular space 122 withthe section 92 of bore 9%). A gasket 124 is disposed around the section121 of the nut and seats on the shoulder W2. A valve disk 126 bearsagainst the lower end of the push rod and extends across the lower endof the packing nut to seal section 93 from the interior of the packingnut when the valve is closed. A horizontal bore 123 in the packing nutprovides a passageway from the packing nut interior to the annular space122. A compression spring 130 is disposed between the valve disk and thebottom of section 94 to urge the valve in a normally closed position.

A slot 137 is formed diagonally across the top of the mixing head andhouses a horizontal lever 134 which is pivotally pinned at its forwardend by a pin 136 friction fitted in a bore 138 through the mixing headat right angles to the slot. A vertical compression spring 13% isdisposed under the lever arm adjacent its rear end to urge the leverinto its uppermost position. A vertical recess 14% in the rear surfaceof the mixing head below the rear end of the lever arm houses a pulleywheel 142 mounted to rotate about a horizontal axis. A vertical bore 144in the mixing head provides communication between the recess and theslot. One end of a flexible cord 46 is attached to the rear end of thelever arm and extends down through the bore 144, around the pulley andrearwardly where it is attached to the forward end of a pin 148 slidablycarried at the lower end of a bracket 149 mounted on the forward portionof the main and bypass conduits. The rear end of pin 1A3 is pivotallyattached to an intermediate part of a downwardly, rearwardly extendingtrigger 1519 which is pivotally attached at its forward end to thebracket just under the main conduit.

The operation of the apparatus is as follows: The second or carrierliquid is delivered through the main conduit by the pump or supplysystem, issuing from the nozzle of the mixing head in the form of apowerful spray or stream, as required. The valve in the mixing head isnormally urged closed, and none of the first liquid is sucked into thecarrier stream until the trigger is actuated. As the first liquid isrequired, the trigger is depressed causing the valve to be opened. Thispermits the carrier liquid to flow through the bypass line and thechemical eductor 4% creating a suction on the leg in the chemicaleductor. The check ball 64 in the suction line is pulled away from thedischarge end of the suction line and the first fluid is pulled into thechemical eductor and the carrier liquid in the bypass conduit and thismixture is then mixed with the carrier fluid emerging from the jet orpassage 82 in the main conduit. The carrier stream is discharged fromthe reduced diameter section 82 into the mixing chamber 89. The combinedflow of carrier liquid and first liquid in the bypass line also flowsinto the mixing chamber 89 through the annular space 84 surrounding thereduced diameter section 82. The mixing chamber in cooperation with thesmall opening 88 in the nozzle 86 confines the combined dischargestreams through the main and bypass conduits and allows the transfer ofenergy from the high velocity discharge stream from the passage d2 ofthe main conduit to the stream from the bypass conduit. The reduceddiameter section 2 in the main conduit is thus in educt-ing relationshipwith the portion of the bypass conduit between the valve in the mixinghead and the mixing chamber.

If a stream of only carrier fluid is desired, the trigger is releasedand the two springs cause the valve in the mixing head to close. Thepressure built up in the bypass line closes the check valve in thesuction line. The carrier fluid continues to flow from the jet and dueto its aspiratin-g action will immediately clear the first liquid out ofthe bore leading from the valve in the mixing head to the annular spacearound the jet. This is particularly important in operations such as rugcleaning where the first liquid is a detergent and any hang up of firstliquid in the mixing head would tend to prevent an efficie-nt rinsing ofthe rugs.

Thus the apparatus of FIGS. 2 through 5 provides a simple but efficientmeans for introducing a first liquid into a second liquid. Furthermore,when the chemical eductor portion of the apparatus is brought into use,the mnount of fluid delivered by the apparatus is increased rather thandecreased since any pressure drop across the main conduit is compensatedfor, at least in part, by the bypass. The amount of increase can varywithin rather wide limits, but in general, with the bypass and mainconduits each wide open, the ratio of flow through the bypass to totalflow can be between /3 to about depending on total pressure available,viscosity of the fluids, pressure drop through the system, dimensions ofthe various elements, and concentration of educed fluid in the finalmixture which is to be produced.

The apparatus of FIGS. 2 through 5 is useful in many types ofapplication, for example, spraying insecticides, washing vehicles,carpets and rugs, mixing fertilizer in irrigation water, etc. and thetype of jet nozzle used in the mixing head will depend upon the use ofthe apparatus. For example, in washing carpets or tugs, a strong,fan-shaped stream is usually desirable. A small, round high velocitystream is usually advantageous in washing vehicles, and a fine spray isusually preferred in distributing insecticides. Any suitable type of jetnozzle arrangement may be used without departing from the scope of thisinvention.

Referring to FIGS. 6 and 7, which show one embodiment of the mixingdevice of this invention adapted to be used in a watering system, agenerally L-shaped housing or body 152 has a bore or opening 154extending through it, and is internally threaded at each end to receiveconventional pipe connections. Beginning at the right-hand end of thebody (as viewed in FIG. 6), a globe type control valve 156 is mounted inthe body and adapted to open or close the bore 154 to control the flowof water or second fluid through the body. As shown by the arrows inFIG. 6, water flows through the body from right :to left. A vacuumbreaker valve 158 is mounted in the body approximately at the pointwhere the body makes a right angle turn. A globe type metering valve 169is mounted in the left-hand and top portion of the body, and includesthe usual gland nut 161, bonnet 1'62, stem 163 and disk 164, which isadapted to bear against an annular seat 165 around a vertical opening165A located at the top of a generally L-shaped partition 16% for-medintegrally with the body under the metering valve.

The partition extends a substantial distance into the body interior toform a bore section 167 which is oval (see FIG. 7) in cross-section,which is substantially smaller in cross-sectional area than theremainder of bore 154. The partition includes a longitudinal bypass boreld into which is press-fitted a chemical eductor bushing 169 having adownwardly extending side leg bore 17% terminating at its lower end inan internally threaded pipe coupling 172 mounted on the lower exteriorportion of the body. ,A suction hose 173 is connected at one end tocoupling 172. The chemical eductor includes a straight, uniformlongitudinal bore 174 joined by a short outwardly tapered bore 175 atits right-hand end. The longitudinal bore 174 is stepped up in diameterat a section 177 at the left-hand end of the eductor. The upper end ofthe side bore 17% opens into the longitudinal bore where it is steppedup in diameter at 177. An overhang 189 is formed integrally with theupper part of the partition. The overhang extends to the left of thepartition and as shown in FIG. 7, the upper surface of the overhang isconcaved upwardly in a plane which is perpendicular to the direction offlow of liquid through reduced section 167. In the plane parallel to thedirection of flow through the reduced section 167, the upper surface ofthe overhang has a slightly upwardly convex curvature. A il-shaped notch182, is cut in the left-hand end of the eductor bus-hing to open in theleft-hand end of the enlarged bore section 177. Ordinarily, the mainflow of water is over the top of the partition and through reducedsection 167, with a relatively minor portion of the water stream beingbypassed through the chemical eductor and section 177. Thus, bore 154-is a main conduit through the body, with the metering valve and reducedsection 167 forming a section of reduced diameter in the main conduit,and the longitudinal straight and tapered bores of the chemical eductorserve as a bypass around a portion of the main conduit.

Referring to FIG. 8, which shows schematically the use of the mixer ofFIGS. 6 and 7, the body is mounted a foot or two above ground level withthe vacuum breaker valve being at the highest point of water flowthrough the body. The right end of the body is connected by an adapter183 to a water supply pipe 134. The left end of the body is connected byan adapter 185 to a water distribution pipe 186 :to which are connecteda series of sprinklers 183, and irrigation bubblers 1%. Other waterdistributing devices can be connected to water pipe 186, if desired.Preferably, the supply and distribution pipe lines 184 and 186 arelarger in cross sectional area than the average bore 154- through themixer body 152 so the velocity of the water is substantially increasedwhen flowing through the body.

To use the mixing device shown in FIGS. 6 through 8, the control valve156 is opened so that water flows through the body from right .to left.The water flow forces a disk 191 in the vacuum breaker valve 158 to moveupwardly and close to air. Assuming that the metering valve 16% issubstantially wide open, practically all the water flow (between about66% and 99% of the total flow) is through the valve and reduced section167 of the main conduit 154. A relatively minor portion of the fluidstream passes through the chemical eductor and bypass conduit 16$. Thewater flowing through the section 167 of the main conduit issues as ahigh velocity 8 V stream into the bore or passage 154 located downstreamfrom the eductor 16%. The stream issuing from the section 167 has amajor velocity component in the direction of the passage 154 and thepassage 154 has a greater cross-sectional area than the section 167. As

a result, the stream issuing from the section 167 seals against thewalls of the passage 154 downstream from the chemical eductor 169 andforms a second or power eductor which transfers energy from the highvelocity discharge stream from the sect-ion 167 to the liquid dischargedfrom the chemical eductor 169.

The water [flowing through the chemical eductor 169 creates a suction inthe side bore 170 and host 173 and aspirates or educts the first fluidfrom the container 194 into the water stream or second fluid" flowingthrough the eductor 169. The mixture of fluids in the outlet 182 of. theeductor 169 are then carried into the Water stream flowing in the bore154 of the main conduit. The water leaves the left-hand end of the bodyand flows out the sprinklers, irrigation bubblers, and any other unitswhich may be attached to the water supply line 186.

As explained above, the metering valve and the reduced section 3'67cause the water in the main conduit to flow in an educting relationshipwith the outlet end of the bypass conduit. It is this arrangement whichpermits the eductor to operate agaiust much higher back pr essures onthe downstream side of the body than previously possible. For example,the pressure differential across the chemical eductor 169 may be quitelarge,

say psi. (pounds per square inch) due to the low pressure area adjacentthe outlet end 182 of the eductor 69 (resulting from theeducting actionof the stream flowing through the passages 167 and 154) even though thepressure drop across the entire mixing device or housing 152 is small,say l0-20 p.s.i., due to a high back pressure. This is a particularlyadvantageous feature, since it permits many various water distributingunits to be connected to line 186 and be operated either all together,one at a time, or any combination in between those two extremes.

The amount of water and the ratio of the first liquid to the secondfluid or water stream flowing out of the mixing device can be regulatedby suitably adjusting valves 156 and If the irrigation bubblers are cutofi by suitable valve means (not shown), the back pressure on theeductor is substantially increased, and at the same time the pressureapplied to the sprinklers is also increased. Thus, the sprinklers tendto oversprinkle or over-water their respective areas, and second, theeductor must operate against a higher back pressure. Due to the eductingrelationship of section 167 in the body, the eductor is capable ofoperating even though there is a substantial increase of back pressure.To avoid overwatering, the control valve or the metering valve, or both,are controlled to reduce the flow of water through the body.

If it is desired to suck the first liquid into the water stream at afixed ratio, it may be accomplished by suita given amount of fertilizeror insecticide over a predeter-mined area. However, if the concentrationof the educed liquid in the water stream must be maintained withincertain limits to be eflective, this is readily accomplished byadjusting the metering valve and the control valve. I

When the watering operation is complete, the main control valve isclosed, and due to the elevated location of the vacuum breaker valve,water drains from the left-hand end of the body to cause the vacuumbreaker valve disk to move down and to open to air and avoid thepossibility.

of any contamination of the water supply system by any remaining tracesof the educed liquid, because the disk seals on an annular seat 192. Thevacuum breaker valve also functions when the water pressure in thesupply line drops, say due to a broken water main, and provides positiveprotection against a contamination. if the watering system is to be usedwithout the eduction of any liquid into the water stream, the end of theeductor is closed either by screwing a plug (not shown) into theconnection 172, or line 173 is closed by a valve (not shown), or air isallowed to be sucked into the main system of water.

FIGS. 9 and 10 show schematically an alternate arrangement in which agate-type valve 195 can be used as the metering valve in place of theglobe-type valve 160 and chemical eductor shown in the apparatus of FIG.6. The valve of FIGS. 9 and 10 includes a body 196 having an inlet 197and an outlet 198. A gate 199' is adapted to be moved up and down byhandle 2% to open the valve and also close it against a seat 201 on theupper edge of an upwardly extending projection or partition 2S2 formedintegrally with the bottom portion of the body 196. The partitionincludes longitudinal bores 2G3 and 2=ll3A extending through it, and adownwardly extending side bore 294 opens at its upper end into thelongitudinal bore 2&3 and at its lower end opens out of .a pipe nippleconnection 205. The bore 203 has a greater cross-sectional area thanbore 203A to permit the stream issuing from bore 263A to create a lowpressure or partial vacuum in the bore 204 as discussed previously. Adeflector 206 is attached to the lower edge and downstream side of thegate so that when the gate valve is partially opened as shown in FIGS. 9and 10, liquid flows from right to left as viewed in FIG. 9 between thelower edge of the gate and the top of the projection to aid the flow ofliquid out the downstream end of the longitudinal bore 203.

FIG. 11 shows schematically another embodiment of the invention in whicha Water stream flows from right to left through a main conduit 2G7, andout a nozzle 2% connected to the left-hand end of the main conduit. Abypass conduit 2&9 is connected at an upstream location 210 and adownstream location 211 to the main conduit. A first eductor 212 is setin the bypass conduit and has longitudinal bores 213 and 213A throughit. The bore 213 has a greater cross-sectional area than bore 213A toprovide the eductor action. A side bore 214 opens at one end intolongitudinal bore 213 and is connected at its other end to a hose 216leading to a supply of a 1I'St liquid such as liquid insecticide 218. Asecond eductor 229 is set in the main conduit at the downstreamlocation. The second eductor also includes longitudinal bores 22 2 and222A of substantially greater diameter than the longitudinal bore 213 ofthe first eductor, and is capable of handling about 6 times more volumeof fluid through its longitudinal bore than the first eductor. Again,the bore 222 has a greater cross-sectional area than the bore 222A. Aside bore 224 opens from the longitudinal bore 222 of the second eductorinto the end of the bypass conduit connected to the main conduit at thedownstream location. A control valve 226 may be used if desired in themain conduit between the upstream and downstream locations to increaseregulation of the amount of fluid bypassed from the main conduit throughthe bypass conduit.

In the operation of the apparatus of FIG. 11, water flows through themain conduit from right to left in a quantity determined by the settingof valve 226. Depending on the setting of this valve, a portion of theliquid flowing through the main conduit is bypassed through the firsteductor, and into the side bore 224 of the second eductor, which exertsan educting effect on the outlet end of the first eductor.

Referring to FIG. 12, which shows the presently preferred embodiment ofthe mixing device of this invention adapted to be used in a wateringsystem such as that shown schematically in FIG. 8, a generally L-shapedhousing or body 23% has an inlet bore 232 formed in its right (as viewedin FIG. 12) end and an outlet bore 234 at its left end. The inner end ofthe inlet bore opens through a globe-type control valve 236 into theright end of a first passageway 238, which opens at its left end througha vacuum breaker backflow valve 240 into a second passageway 242 locatedapproximately where the body is bent at a right angle. The left end ofthe second passageway opens through a globe-type metering valve 244 intothe right end of a third passageway 246, which is tapered to a reducedcross-sectional area at its left end where it opens into the right endof the outlet bore, which is substantially larger than the thirdpassageway. The first, second, and third passageways, along with theinlet and outlet bores, form a main conduit through the body throughwhich a major portion of the water flows. A bypass conduit 248 isconnected at its right end to the right end of the second passageway. Achemical eductor bushing 250 is press-fitted into an enlarged bore 251opening into the left end of the bypass conduit. The chemical eductorbushing includes a straight uniform longitudinal bore 252 which opens atits right end into a short outwardly tapered bore 254 located at theright end of the chemical eductor bushing. The left end of thelongitudinal bore 252 opens into a tapered bore 254 located at the rightend of the chemical eductor bushing. The left end of the longitudinalbore 252 opens into a tapering bore 256 at the left end of the chemicaleductor bushing. A downwardly extending lateral bore 258 in the eductorbushing opens at its upper end into the longitudinal bore where thelongitudinal bore joins the tapered bore 254. The lower end of thelateral bore opens into an annular recess 260 around the intermediateportion of the eductor bushing, which is in communication at its lowerportion with a downwardly extending side bore 262 in the body 230. Sidebore 262 opens at its lower end into an in ternally threaded pipe nipple264 into which is threaded a supply hose 266 for a first, or educed,liquid.

The general flow of fluid through the body 23% is from right to left asshown by the arrows in the drawing. The left end of the chemical eductorbushing extends slightly out into the junction of the third passagewayand the outlet bore so that it is in effect surrounded by the stream ofliquid flowing into the outlet bore. The cross sectional area of themain conduit is general-1y elliptical and similar to that shown in FIG.7 for the reduced section 167. However, in the device of FIG. 12, thecurvature of the third passageway 246 is concave upwardly in the planeof the drawing of FIG. 12 so that the direction of flow of liquid fromthe main conduit is more nearly parallel with that flow through thechemical eductor. This arrangement provides a greater educting effect onthe liquid discharged from the chemical eductor than does the apparatusof FIGS. 6 and 7.

To use the mixing device of FIG. 12, the control valve 236 is opened sothat water flows through the body from right to left. The water flowforces a disk 268 in the vacuum breaker valve to move upwardly and closeto air. Depending on the setting of the metering valve 244, the flow ofwater through the body is split into two streams at the right-hand endof the second passageway. A minor portion of the water stream goesthrough the bypass conduit and the remainder of the water flows throughthe third passageway. At the left end of the chemical eductor where thetwo streams rejoin, the flow of water from the main conduit throughpassages 246 and 234 exerts a strong educting effect on the dischargeend of the chemical eductor. In fact, with the right-hand end of theeductor longitudinal bore plugged, a vacuum of 15" of mercury wasdeveloped in the apparatus shown of FIG. 12 by simply flowing waterthrough only the third passageway with a supply pressure of about psigat the inlet bore. It is this strong educting effect exerted by the flowof water from the main conduit which permits the eductor arrangementshown in FIG. 12 to operate against surprisingly high back pressures. Inan actual test with the apparatus l l. of FIG. 12, with the eductorunplugged, and the metering valve wide open, a suction of 26.4" ofmercury was developed in hose 266 against a back pressure of 20 p.s.i.g.with a supply pressure of about 67 p.s.i.g. Even when the back pressurewas increased to 42 p.s.i. g., there still was developed in the hose 266a vacuum of of mercury, which is more than adequate to educt virtuallyall liquids at a satisfactory rate into the water flowing through thebody.

It should be noted that the passages 2.46 and 234 form a second jet pumpeductor in the apparatus shown in FIG. 12. It is this second eductorthat creates the strong educting effect that aids the operation of theeductor 250. In the apparatus shown in FIGS. 2-5, 6, and 9-10, thereduced section of the main conduit entering into the main conduit oflarger cross-sectional area adjacent the downstream location of thebypass conduit also forms a second eductor. This second eductor resultsfrom the reduced section of the main conduit being in eductingrelationship with the bypass conduit.

Although many different types of chemical eductors in the bypass conduitcan be used, I have found that the tapered type shown in FIG. 12operated most satisfactorily over a wide range of supply pressures andback pressures. Also, it is preferable for the flow through the chemicaleductor to discharge into an enlarged chamber, such as that shown inPEG. 12, and preferably substantially coaxially into the outlet bore sothat the high velocity jet from the chemical eductor is located in thecenter of the liqiud stream flowing out the outlet bore, where theliquid velocity is at a maximum.

From the foregoing examples, it will be apparent that the compoundededucing arrangement of this invention permits a greater total liquidthroughout for a given ratio of educed liquid to carrier liquid thanpreviously possible because of the relatively large suction developedwith a minimum amount of pressure drop in the main conduit.

1 claim:

1. Apparatus for introducing a first liquid into a carrier stream of asecond liquid comprising a main conduit adapted to be connected to asource of the second liquid, a bypass conduit opening into the mainconduit at an upstream and a downstream location, an eductor in thebypass conduit, and a section in the main conduit of a diameter lessthan that of the remainder of the main conduit, the section beingdisposed adjacent the said downstream location in educting relationshipwith the portion of the bypass conduit between the eductor and thedownstream location.

2. Apparatus for introducing a first liquid into a carrier stream of asecond liquid comprising a main conduit adapted to be connected to asource of the second liquid, a bypass conduit opening into the mainconduit at an upstream and a downstream location, an eductor in thebypass conduit, the eductor andbypass conduit being of such sizerelative to the main conduit so as to bypass a relatively minor portionof the flow of second liquid while the relatively major portion of thesecond liquid flows through the rnain conduit, a first passage in themain conduit adjacent and upstream from said downstream location, and asecond passage in the main conduit downstream from said downstreamlocation, the second passage having a greater cross-sectional area thanthe first passage and being arranged to seal the stream of liquidissuing from the first passage, whereby the fluid in the bypass conduitis educted into the stream issuing from the first passage.

3. Apparatus for introducing a first liquid into a carrier stream of asecond liquid comprising a main conduit adapted to be connected to asource of the second fluid, a bypass conduit opening into the mainconduit at an upstream and a downstream location, an eductor in thebypass conduit, a section in the main conduit of a diameter less thanthat of the remainder of the main conduit, the section being disposedadjacent the said downstream location in educting relationship with theportion of the bypass conduit between the eductor and the downstreamlocation,

and a valve in the main conduit between the upstream and downstreamlocation.

4. Apparatus for introducing a first liquid into a carrier stream of asecond liquid comprising a main conduit adapted to be connected to asource of the second liquid,

a bypass conduit opening into the main conduit at anupstream and adownstream location, a first eductor in the bypass conduit, meansconnecting the source of the first liquid to the first eductor so thatthe first liquid is educted into the carrier stream of the second liquidflowing through the first eductor, and a second eductor in the mainconduit at the downstream location, the second eductor having a sidebore opening into the downstream end of the bypass I conduit.

5. Apparatus for introducing a first fluid into a carrier stream of asecond fluid comprising a main conduit adapted to be connected to asource of the second fluid, a bypass conduit opening into the mainconduit at an upstream location and a downstream location, an eductor inthe bypass conduit for the intake of the first fluid, a valve a mainconduit adapted to be connected to the pump dis-.

charge and permit the second fluid to flow at substantially the ratedcapacity of the pump, a bypass conduit opening into the main conduit atan upstream location and a downstream location, an eductor in the bypassconduit for the intake of the first fluid, a valve in the bypass conduitbetween the eductor and the downstream location, and

a reduced diameter section in the main conduit adjacent the downstreamlocation in educting relationship with the portion of the bypass conduitbetween the downstream location and the valve.

7. Apparatus for introducing a first fluid into a carrier,

stream of a second fluid comprising a main conduit adapted to beconnected to a source of the second fluid, a bypass conduit opening intothe main conduit at an upstream location and a downstream location, aneductor in the bypass conduit for intake of the first fluid, means forcontrolling the flow of the first fluid independent of the flow of thesecond fluid through the main conduit, a reduced diameter section in themain conduit adjacent the said downstream location, and a common mixingchamher into which the reduced diameter section and bypass conduitdischarge, the bypass conduit opening into the mixing chamber around thesaid reduced diameter section.

8. Apparatus for introducing a first fluid into a carrier stream of asecond fluid comprising a main conduit adapted to be connected to asource of the second fluid, a bypass conduit opening into the mainconduit at an upstream location and a downstream location, an eductor inthe bypass conduit for intake of the first fluid, means for controllingthe flow of the first fluid independent of the flow of the second fluidthrough the main conduit, a

reduced diameter section in the main conduit adjacent the saiddownstream location, and a common mixing chamber into which the reduceddiameter section and bypass conduit discharge, the bypass conduitopening into the mixing chamber around the reduced diameter section, themixing chamber having an outlet opening which is reduced in diametertoward the outer end of the outlet opening.

9. Apparatus for introducing a first fluid into a carrier stream of asecond fluid comprising a main conduit adapted to be connected to asource of the second fluid,

a bypass conduit opening into the main conduit at an upstream locationand a downstream location, an eductor in.

the bypass conduit for intake of the first fluid, means for controllingthe flow of the first fluid independent of the flow of the second fiuidthrough the main conduit, a reduced diameter section in the main conduitadjacent the said downstream location, and a discharge nozzle connectedto the main conduit and having an outlet opening which decreases in sizetoward its outlet end, the reduced diameter section discharging into theinlet end of the noz zle and forming an annular channel between theinlet end of the nozzle and the discharge end of the reduced diametersection, the bypass conduit opening into the annular channel so that thereduced diameter section and nozzle educt with respect to the bypassline.

10. Mixing apparatus comprising a body having an opening through it witha liquid inlet at one end of the opening and a liquid outlet at theother end, a partition attached to the body interior extending into thebody to be spaced from a portion of the body interior to form a sectionof reduced cross sectional area in the body, an eductor mounted in thepartition, the eductor having a longitudinal bore opening on oppositesides of the partition and a side bore opening at one end into thelongitudinal bore and opening at the other end out of the body, meansfor flowing liquid through the body from the inlet toward the outlet toforce liquid through the longitudinal bore of the eductor, and means fordirecting flow of liquid through the section of reduced cross sectionalarea in the same general direction as liquid flowing through thelongitudinal bore.

11. Mixing apparatus comprising a body having a main bore through it toprovide an inlet and an outlet, a partition attached to the bodyinterior and extending into the main bore to be spaced from a portion ofthe body interior to form a section of reduced cross-sectional area inthe main bore of the body, a metering valve seat formed on thepartition, a metering valve disk mounted in the body adjacent themetering valve seat, means for moving the metering valve disk toward andaway from the metering valve seat to close and open the space betweenthe partition and the said portion of the body interior, an eductormounted in the partition to bypass the metering valve disk, the eductorhaving a longitudinal bore opening on opposite sides of the partitionand a side bore opening at one end into the longitudinal bore andopening at the other end out of the body, and a vacuum breaker valvemounted in the body upstream from the eductor to open the main bore whenthe pressure in the body exceeds atmospheric pressure, and to close themain bore and admit air into the body when the pressure in the body isless than atmospheric pressure.

12. Apparatus for introducing a first liquid into a carrier stream of asecond liquid comprising a main conduit adapted to be connected to asource of the second liquid, a bypass conduit connected to the mainconduit to form a first opening at an upstream location and a secondopening at a downstream location, an eductor in the bypass conduit,means defining a first passage in the main conduit adjacent and upstreamrromthe second opening, means defining a second passage in the mainconduit downstream from the second opening, the second passage being ofgreater cross-sectional area than the first passage and arranged so thatthe stream of the second liquid issuing from the first passage sealsagainst the walls of the sec ond passage, whereby a low pressure area iscreated surrounding the second opening and the liquid in the bypassconduit is aspirated into the carrier stream flowing through the firstpassage.

13. Apparatus as defined in claim 12 wherein the first passage isarranged to direct the stream flowing therethrough into the secondpassage with a major velocity component of the stream being in the samedirection as the second passage. 7

14. Apparatus for introducing a first liquid into a carrier stream of asecond liquid comprising a main conduit adapted to be connected to asource of the second liquid, a bypass conduit opening into the mainconduit at an upstream and a downstream location, a first jet pumpeductor in the bypass conduit, means for connecting the first eductor toa source of the first liquid so that the first liquid will be eductedinto the liquid flowing'through the first eductor, means forming asecond jet pump eductor in the main conduit adjacent the opening of thebypass conduit at the downstream location, the second eductor beingarranged to educt the liquid in the bypass conduit into the carrierstream flowing through the main conduit, whereby the first liquid may beefiiciently educted into the second liquid with a very small pressuredrop across the second eductor.

References Qited in the file of this patent UNITED STATES PATENTS1,458,975 Clauson June 19, 1925 2,316,781 Fox Apr. 20, 1943 2,599,678Walker June 10, 1952 2,692,608 Clearman Oct. 26, 1954 2,711,928 R andaJune 28, 1955 2,856,234 McNair et :al Oct. 14, 1958 2,868,584 Faust Jan.13, 1959 2,881,782 Nash Apr. 14, 1959 UNITED STATES PATENT OFFICECERTIFICATE OF CORRECTION Patent No. 3.lO4,825 September 24, 1963Stanley A. Hayes ears in the above numbered pat- It is hereby certifiedthat error app s Patent should read as ent requiring correction and thatthe said Letter corrected below.

lines 23 to 25 strike out "The left end of e 252 opens into a taperedbore 254 f the chemical eductor bushing."

Column 10, the longitudinal bor located at the right end 0 Signed andsealed this 21st day of April 1964.

(SEAL) Attest: EDWARD J BRENNER ERNEST W. SWIDER Attesting OfficerCommissioner of Patents

1. APPARATUS FOR INTRODUCING A FIRST LIQUID INTO A CARRIER STREAM OF ASECOND LIQUID COMPRISING A MAIN CONDUIT ADAPTED TO BE CONNECTED TO ASOURCE OF THE SECOND LIQUID, A BYPASS CONDUIT OPENING INTO THE MAINCONDUIT AT AN UPSTREAM AND A DOWNSTREAM LOCATION, AN EDUCTOR IN THEBYPASS CONDUIT, AND A SECTION IN THE MAIN CONDUIT OF A DIAMETER LESSTHAN THAT OF THE REMAINDER OF THE MAIN CONDUIT,